Around 60,000 pensioners in Scotland will spend Christmas day alone
The Age Scotland figures are a 50% increase on 2015, showing a surge in the "epidemic'' of loneliness.
Age Scotland is launching its "No one should have no one'' campaign to highlight the extent of loneliness and isolation across the country.
Brian Sloan, chief executive of the charity, said: "The epidemic of loneliness among older people is having a devastating impact on their health and wellbeing.
"While most of us are looking forward to spending the festive period with family or friends, it's sobering to think that 60,000 older Scots will have only their television for company.
"Many more will go for days without a visit or even a phone call from family or friends.
"It's heart-breaking that so many people lose their confidence and sense of self-worth as they get older.
"We hear from older people via our helpline who feel trapped in their homes and simply want to hear the sound of a human voice.
"We have regular callers who call to ask what day or time it is as their days are so repetitive, or say they sleep most of the day as there's nothing else to do.''
Loneliness can have a serious impact on both physical and mental health, causing long-term "misery'' and contributing to the development of serious medical conditions such as heart problems, mental health issues and dementia.
Around 80,000 people over 65 feel lonelier at Christmas time than at any other time of year, with those who have been widowed most at risk, according to the study.
The same number see TV as their only source of company over festive period, with nearly one in five keeping it on all day because "it's lovely to hear human voices''.
Almost one in 10 older people will spend half or more of their days alone over Christmas, without a phone call or visit from a friend or relative.
The research shows one in 10 older Scots leave their home only once a week or less often, while 3% do not usually leave their home in a month.
Mr Sloan gave his backing to a Scottish Government commitment to tackle loneliness.
He added: "We can also all do our bit to reach out to older people in our communities, whether that's volunteering as a befriender or simply popping round to check on a neighbour.
"Something as simple as taking time for a chat and a cuppa can make a huge difference to the well-being and happiness of a lonely older person.''
The study interviewed 2,585 adults over 65 across the UK, including 268 in Scotland, with figures weighted to represent all Scottish OAPs